For gold making purposes, there are four general ways to accomplish that with professions. 1) cooldowns, 2) BoP reagent usage (Expulsom, etc) 3) rare recipes, and 4) gathering.

Evaluating the profession value requires something specific to the profession. For instance the Vial of the Sands (Alchemy Mount, all reagents BoE) based on wowhead prices sells for about 90k and is made of pieces that sell for 86k. Assuming a mount was sold for 90k, after the 5% AH cut, only 85.5k would be received. Since it's not worth directly buying the reagents to craft the mount, the value of the mount recipe is basically 0. Any value earned from crafting the mount is due to the value of collecting the reagents, not due to the value of performing the combining. If the mats sell for about the same as the item, the value is in the mats, not the crafting.

The value in #1 is fairly consistent and useful. Alchemy is a perennial choice. Darkmoon cards and Inscription is often good at the start of an expansion. I am not playing BfA currently, so research the specifics yourself.

The value in #2 is likely minimal in the absence of #1 (if there's a daily conversion limit either to Expulsom or to items, then value, otherwise, anyone could gather Expulsom and do the crafting)

The value in #3 is generally minimal, exceptions made for recipes no longer in game since it doesn't take that many interested parties to make the crafted price be close to the mats price.

The value in #4 is magnified for multiboxers since nodes can be harvested up to 10x. Single boxers only get 1 set of herbs, multiboxers get up to 10.


My suggestion would be for gathering professions if you're willing to devote time to earning gold with professions as multiboxers have a unique advantage here and to focus on cooldowns if you're not.

Edit: If you have multiple teams/characters per account, then gathering on one set (druids?) and cooldowns on the others